Implementation of Bronchoscopic Lung Volume Reduction Using One-Way Endobronchial Valves: A Retrospective Single-Centre Cohort Study

A preclinical animal study to evaluate the operability and safety of domestic one-way endobronchial valves

Purpose

To evaluate the operability and safety of bronchoscopic domestic one-way endobronchial valves (EBV) on animals.

Methods

Nine pigs were randomly assigned (2:1) to receive domestic one-way EBV (the experimental group, n = 6) and Zephyr® EBV (the control group, n = 3). Routine blood tests, arterial blood gases, and CT scans of the lungs were performed 1 day pre-procedure in addition to 1 week and 1 month post-procedure to assess changes in blood markers and lung volumes. At 1 month post-procedure, the animals were sacrificed, followed by removal of all valves via bronchoscopy. Pathological examinations of critical organs were subsequently performed.

Results

A total of 15 valves were placed in the experimental group and 6 valves were placed in the control group, without serious complications. Routine blood tests and arterial blood gas examinations at 1 day pre-procedure, 1 week post-procedure, and 1 month post-procedure did not differ significantly in both groups. No EBV displacement was noted under bronchoscopy, and the valve was smoothly removable by bronchoscope at 1 month post-procedure. At 1 week post-procedure, varying degrees of target lung lobe volume reduction were observed on lung CT in both groups. Lung volume reduction was achieved at 1 month post-procedure in both groups, without significant statistical difference. Although 3 cases in the experimental group and 1 case in the control group developed varying degrees of pneumonia, the inflammatory response did not increase over time during the experimental period. Pathological examination revealed no significant abnormal changes in the critical organs for both groups.

Conclusion

Our results demonstrate that domestic EBV is safe and reliable for endobronchial application in general-grade laboratory white pigs. The safety of domestic EBV is similar to that of Zephyr® EBV, with good ease of use and operability. This kind of domestic EBV can meet the safety evaluation requirements for animal testing.

Lung Resection for Non-Small Cell Lung Cancer following Bronchoscopic Lung Volume Reduction for Heterogenous Emphysema

Bronchoscopic lung volume reduction (BLVR) is a minimally invasive treatment for emphysema. Lung cancer may be associated with emphysema due to common risk factors. Thus, a growing number of patients undergoing BLVR may develop lung cancer. Herein, we evaluated the effects of lung resection for non-small cell lung cancer in patients undergoing BLVR. The clinical data of patients undergoing BLVR followed by lung resection for NSCLC were retrospectively reviewed. For each patient, surgical and oncological outcomes were recorded to define the effects of this strategy. Eight patients were included in our series. In all cases but one, emphysema was localized within upper lobes; the tumor was detected during routine follow-up following BLVR and it did not involve the treated lobe. The comparison of pre- and post-BLVR data showed a significant improvement in FEV1 (29.7 ± 4.9 vs. 33.7 ± 6.7, p = 0.01); in FVC (28.5 ± 6.6 vs. 32.4 ± 6.1, p = 0.01); in DLCO (31.5 ± 4.9 vs. 38.7 ± 5.7, p = 0.02); in 6MWT (237 ± 14 m vs. 271 ± 15 m, p = 0.01); and a reduction in RV (198 ± 11 vs. 143 ± 9.8, p = 0.01). Surgical resection of lung cancer included wedge resection (n = 6); lobectomy (n = 1); and segmentectomy (n = 1). No major complications were observed and the comparison of pre- and post-operative data showed no significant reduction in FEV1% (33.7 ± 6.7 vs. 31.5 ± 5.3; p = 0.15) and in DLCO (38.7 ± 5.7 vs. 36.1 ± 5.4; p = 0.15). Median survival was 35 months and no cancer relapses were observed. The improved lung function obtained with BLVR allowed nonsurgical candidates to undergo lung resection for lung cancer.

Bronchoscopic Lung Volume Reduction: Highlighting the Patient Selection Process

Patients with advanced emphysema frequently experience severe dyspnea that is inadequately treated with medical therapy alone. Over the past 4 years, we have seen increased usage of bronchoscopic lung volume reduction (BLVR) with endobronchial valves. Success of the procedure is dependent on patient selection because it is not necessarily appropriate for all patients with severe emphysema. (Table 1) The purpose of this review is to highlight the selection process at a single institution. We also discuss the influence of this process on outcomes. Between March 1, 2019, and October 12, 2021, 2402 patients were referred to a dedicated chronic obstructive pulmonary disease clinic at Mayo Clinic - Rochester, whereas 161 patients were subsequently referred for multidisciplinary BLVR review. Of those patients, 53 (32.9%) were selected to receive valves and 35 (21.7%) ultimately underwent the procedure. The main reasons for exclusion included an incompatible quantitative computed tomography analysis (n=37, 34.3%), presence of pulmonary nodule or active malignancy (n=14, 13.0%), or need for completion of pulmonary rehabilitation (n=9, 8.3%). Full or partial (>70%) target lobe collapse was observed in 58.6% of patients who received valves. Those with collapse experienced statistically significant improvements in spirometric measures. Twelve patients experienced a pneumothorax (34.3%), with 10 patients requiring thoracostomy tube placement and prolonged hospitalization (median, 11 days; range, 4-39 days). Nineteen patients required a secondary procedure within the first year. The study highlights how a multidisciplinary approach to the BLVR selection process enables individualization of a complex procedure and enhances the exclusion of inappropriate candidates.